1. Field of the Invention
This invention relates to an all terrain vehicle and more particularly to the placement and orientation of the engine and type of engine and power train.
2. Description of Related Art
All terrain vehicles have become quite popular in Canada and the United States in recent years. The original vehicles were built with three wheels and had a chain drive. Motors were generally oriented in the vehicle, having the crankshaft and drive shafts oriented transversally to the direction of travel. Such vehicles were found to be unsteady and did not have sufficient stability and power to work as utility vehicles.
In more recent years, all terrain vehicles have been developed with four wheels for greater stability and in fact four wheel drive. Generally, the orientation of the motor was such that the crankshaft and drive shafts extended transversally to the line of travel and chain drives or other gear mechanisms were used to drive front and rear axles.
In very recent times, some manufactures have oriented the engine such that the crankshaft is parallel to the line of travel and the longitudinal axis of the vehicle. In fact, some vehicles have a single output or drive shaft which extends through the motor and drives transmissions on the front and rear axles. Being a single shaft of course the gear ratio is identical between a front portion of the single output or drive shaft and a rear portion of the single output or drive shaft.
Other problems with recent all terrain vehicles is the failure to provide access to the engine for maintenance and repair. It is difficult to access things such as the oil filter, engine oil filler cap or remove the cylinder head. Therefore, there is a need to have a vehicle with ready access to the engine.
Another problem with recently manufactured all terrain vehicles is that the engine is too high and takes up too much space. Therefore a new more compact engine is desirable. Another problem with present day engines is failure to have a parking gear. The parking gear is desirable when one wishes to keep the engine on or park on a steep slope. It is also desirable to have engine placement in such a way so that the vehicle can be easily mounted by the operator without stepping over a high straddle seat. Thus there is a need to position the engine such that one may step through to mount the saddle or seat.